The judges did what judges are supposed to do, which is to interpret the law.
Although Cameron's government said they would obey the decision of the people, that was only a political promise, like in a manifesto, not a commitment that they were legally entitled to make.
So, basically yet another Cameron cockup:
our former PM ignored, or was ignorant of, the British Constitution.
He could have avoided all this muddle by specifically writing in the Referendum BIll that it was legally binding (like the AV Referendum was) but he didn't.
In fact, it was stated in a Parliamentary answer at the time of the Bll that it was advisory only.
The constitutional way to activate Article 50 is for Theresa May to gird her ovaries and introduce a simple bill in Parliament to do so.
She can make it a 3-line whip and remind MPs that any who oppose this have to answer to their local Tory or Labour party - who can deselect them - or their voters at the next GE - who can elect someone else.
She can also pass a bill to repeal the Fixed Parliament Act and then call a GE, say in 2018 with the new boundaries.
Corbyn is a once-in-a-lifetime gift to her: she'd get a huge majority - with some MPs deselected - and a mandate to do Brexit her way.
If she really intends Brexit, that's what she'll do.
However, if this whole Brexit exercise was just to keep the Tory Party together but it got out of hand .....